Many conventional image projectors include a display that modulates an illuminating light beam. The illuminating light beam may be a white light provided by a light source, such as metal halide lamps, xenon lamps, or mercury lamps. On the other hand, the illuminating light beam may include three separate color light beams, which are red, green, and blue light beams. Each color light beam may be separately provided by a light emitting diode (“LED”), a laser diode, or other types of laser such as gas laser, solid state laser, etc. The display panel may be a digital micro-minor device (“DMD”) or micro-electro-mechanical system (“MEMS”) such as in a digital light processing (“DLP”) display system. The display panel may also be a liquid crystal display (“LCD”) or liquid crystal on silicon (“LCOS”) display.
Lasers have some advantages over other light sources. For example, their lifespan is about 10,000 hours in contrast to an approximately 1,500 hours of lifespan of mercury lamps. Lasers may also provide a wider color gamut as compared with traditional light sources. In addition, a laser light source is compact in size, which may be more suitable for a pico projector. A pico projector is a projector used in handheld devices such as mobile phones, personal digital assistants, digital cameras, etc, which have little space to accommodate an attached display screen. Thus, a displayed image is projected onto any nearby viewing surface such as a wall. Advances in image projectors that use laser light sources expand the application and use cases of image projectors.